


Knot Part of My Repertoire

by captain_americano



Category: Supernatural
Genre: Alternate Universe - Supernatural, Anal, Anal Sex, Bestiality, Familiar!Castiel, First of all I'M SO SORRY, Knotting, M/M, Nipple Play, Other, Porn Without Plot, Rimming, Sex, Sex with Sentient Animals, Smut, Witches, dog!Castiel, familiar, once more I'm very very sorry, witch!Dean
Language: English
Status: Completed
Published: 2015-01-31
Updated: 2015-01-31
Packaged: 2018-03-09 20:02:21
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,729
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3262574
Author URL: https://archiveofourown.org/users/captain_americano/pseuds/captain_americano
Summary: <blockquote class="userstuff">
              <p>Supernatural au, but not canon divergence. Dean is a witch, Cas is his familiar, taking the form of a husky. Dean often does the do with Cas in his human form, but somehow Dean finds his curiosity wandering, and Cas telepathically sees that Dean is wondering what it would be like to get funky with Cas in his dog form. Cas, being the adoring familiar he is, gives his master his wish. SORRY. VERY SORRY. READ THE MF TAGS, OKAY?!</p>
            </blockquote>





	Knot Part of My Repertoire

**Author's Note:**

> DON'T LIKE? DON'T READ. And certainly don't leave a rude comment, because I will respond with sass. Just ask the first commenter *glares*.   
> I wrote this back at the beginning of December. That's how long it took me to decide whether or not to acknowledge the existence of this fic.

When Dean had first spotted the colossal dog, he hadn't felt terrified or disgusted like he did with dogs normally; he'd felt drawn to the beast. When the dog had followed him home, he, being the advanced witch he was, understood. This dog was his familiar spirit, it had chosen him to be it's master.

He had allowed the husky into his home, upon which the dog had transformed into -- of all human forms -- a tall, dark haired male, with eyes precisely the same shade of blue as the dog's.

"I'm Dean," he had introduced himself, for lack of anything better to say.

The man had cocked his head and stared at Dean intently, and he simply said, "I know."

Eventually Dean had coaxed a name out of his familiar, and they began their friendship, eventually developing into a relationship. Their connection -- their 'profound bond' as Castiel, or Cas, liked to call it -- was curious, peculiar, different, compared to other witches and their familiars.

That was, of course, putting it politely. Some others in their community were disgusted and confused by their particular relationship, but there was never any real justification to their judgement. Dean and Cas only ever lay together as men, and there was definitely no plans to change that.

Until there was.

In Dean's defense, it really wasn't an actual plan, or even really an idea… it was just a fleeting moment of rare curiosity that he immediately shoved aside.

Unfortunately, Castiel, the observant, sensitized creature he had proven to be time and time again, had caught the notion, and ran with it.

Generally, as a rule of thumb, Castiel preferred his human form. He usually only ever changed into his husky form when he felt threatened, or scared, or was sulking for a particular reason (most recently after Dean had yelled at him for pulling apart the toilet roll in a fit of boredom one day while Dean was at work).

That was why Dean was a little confused, a little concerned, when he came home to find Cas wagging his tail and licking at Dean's fingers as he wandered further into the house.

"What's up, buddy, the mailman try to get in here again?" He chuckled, despite the fact he was genuinely a little worried, not to mention the fact that Cas was purposely blocking their telepathy.

In response, Castiel let out a small _'woof'_ that sounded, if anything, like a huff of annoyance.

"I know, that was rude. What's up, Cas?" Dean dropped his briefcase and sank into the lounge, patting the space next to him. Cas jumped up with agility, and pressed himself right against Dean, undoubtedly covering his suit in hair. Whatever.

Then, Castiel started licking his face, which was _kind of_ gross. Human Cas wouldn't do that, and Dean wouldn't let any regular dog do that, but it also felt kind of nice… the smooth, warm tongue running over his face.

Dean was squirming and half trying to push Cas off, but the dog was relentless. Dean's traitorous mind suddenly flicked to where it had only gone to a few, brief, dark times, as he wondered what it would be like to have that giant tongue elsewhere.

Suddenly, Cas' tongue was gone, and his nose was pressing at Dean's crotch, and Dean could hear him inhaling deeply.

"Uh, Cas?" Dean said, halfheartedly pushing the dog away. Castiel paused to lightly nip at Dean's arm, before continuing. Castiel started pawing at Dean's fly, and that was more painful than anything.

"Cas, c'mon, what's got into you, bud?" Dean tapped the dog on his nose, and Castiel looked up at him with big, blue puppy-dog eyes. Literally. "Will you let me in?"

All of a sudden, Dean's mind was flooded with images he'd been repressing for god only knows how long and, oh, Cas wanted this too.

"Shit," he huffed, overwhelmed with Castiel's thoughts and the insta-boner that left his head spinning.

"Wuff," Cas agreed, lapping at Dean's neck.

Dean gently nudged the dog off his lap and stood, brushing the excess hair from his suit.

"C'mon, then, boy," Dean said hesitantly, watching Cas jump off the lounge and wag his tail enthusiastically.

Dean headed up the stairs, and heard the telltale clipping of Castiel's nails on the hardwood floor, following him.

Dean stood at the foot of their bed and watched Cas stroll into the room, his tail wagging like mad. Cas wandered over to Dean and started sniffing his crotch again.

"Yeah, yeah, alright," Dean grumbled, shrugging out of his coat and unbuttoning his shirt, before shrugging that off, too.

He kicked his shoes and socks off and hesitated before unzipping his pants. What if this was a joke? What if Cas turned into a human the second Dean was naked and was disgusted by him?

He looked down as a low growl erupted from the husky who had apparently been listening to his inner monologue. The dog seemingly glared up at him, and Dean got the message -- disrobe.

Dean quickly stepped out of his pants and boxers, and was suddenly forced back onto the bed by sixty pounds of dog.

"Watch the paws, man," Dean grumbled as he felt Castiel's nails leave angry marks on his chest from the attack, but Castiel just started trailing his cold, wet nose over Dean's torso.

While Dean may technically be the 'master' or whatever their society liked to label him, he and Cas were always on equal terms, and Dean was a total bottom, so Castiel took his experience and put it to practice in his dog form.

Dean shuddered, gripping the duvet tightly when Castiel ran his cold nose over Dean's nipple, following the motion with the warm lave of his tongue. He continued this treatment over and over, switching between nipples, before moving completely onto the left side of Dean, and nudging his nose under Dean's torso.

Without needing their telepathic communication, Dean knew this to mean 'roll over' and might have chuckled at the switch in human/dog roles, if he wasn't so fucking turned on.

He flipped himself onto his hands and knees, his dick hanging heavy as he felt Cas shift behind him, and his stomach clenched as he felt hot breath over his hole.

Oh god, yep, this was really happening. Dean shoved his face into the pillow with a loud groan at the first touch of Cas' long, slobbery tongue, merely lapping over his hole.

Less than a minute later, Dean felt the tongue breaching his hole, he could feel the short, bristly hairs pressed right up against his ass cheeks as Cas ate him out, his long, doggy tongue reaching places Cas' human tongue couldn't, sending Dean wild.

Cas kept at it for what felt like hours, until Dean was shaking with need. All of a sudden, the tongue was gone, and Dean whined.

 _Finger yourself open,_ Cas commanded, lapping at the sweat that had gathered on Dean's lower back. Dean barely had the brainpower to reach into the nightstand and grab the lube, but somehow he forced his body to do it, and then he was covering his fingers, despite the fact Cas had already worked him open well enough.

When Dean felt he was prepared, he glanced over his shoulder to see the dog looking at him hungrily, and further down Castiel's fucking doggy dick was bright pink out of its sheath. Instead of feeling creeped out, like he _should_ have been from the get-go, Dean felt a drop of precome leak from his own dick.

He reached over to Cas and lubed up the dog's cock, all too aware that he was presenting himself to Cas like a bitch in heat.

Before he even had a moment to breath, he felt Cas mounting him, the dog's front paws framing his waist as Castiel shuffled forward until his dick met Dean's hole.

Dean groaned as he felt the dog push in, smaller than human Cas' but just as much of a turn on, the complete and utter _wrong_ making it maybe even just a little bit hotter.

Then, like human Cas was long gone, the dog on top of him started fucking into him like a wild beast, the jackhammer pace almost bringing tears of pleasure to Dean's eyes. Somehow, through whatever primal urge was taking over the dog, Cas managed to hit Dean's prostate with each fast thrust.

Dean couldn't hold himself, and the dog on top of him, up and wrap a hand around his dick at the same time, but at that stage, he knew he was about to blow any second, at least, until something started feeling funny.

He could feel Cas' dick getting bigger and bigger around the base, and, oh _fuck,_  he hadn't even considered the possibility of Cas knotting him!

Cas slammed in one last time and tugged, but didn't come out, so instead he just gave shallow, wiggling thrusts, nudging Dean's prostate repetitively.

The burn of Castiel's knot, the wrongness of the situation, and the stimulation were all combined to have Dean coming like a freight train, with a cry. He felt himself squeezing around Cas, and suddenly, with a very doggy whine, he felt Castiel pumping his dog-come into Dean's hole, and if Dean were a younger man, he would've already been half-mast again by now.

"Fuck, Cas," he whimpered into his pillow, feeling the knot tugging at his abused hole. Cas let out a low, apologetic whine, and Dean felt the body on top of him change.

Dean slumped onto the mattress as the human dick slipped out of him, and he felt Castiel's strong, human arms wrap around him.

"I am sorry, Dean," Castiel said in his gravelly voice that Dean always missed while the man was in his dog form, "I did not take canine anatomy into the equation."

"Neither did I," Dean admitted, rolling over to face Cas and reciprocate his embrace.

"Was that okay?" Castiel asked, looking concerned. Dean buried his face in Cas' neck in embarrassment as he nodded fervently.

"Very okay," he admitted, "but maybe next time…"

"What, Dean?" Castiel urged, stroking Dean's hair lovingly.

"Next time, can you… stay for a bit longer?" Dean asked in a mortified whisper.

Castiel let out a low chuckle and pressed a kiss to Dean's temple, "Of course, love."

**Author's Note:**

> So, at ass o'clock one morning last year I thought a hilarious pun of an a/b/o type of fic would be "knot part of my repertoire" but it didn't really make as much sense for a/b/o as it did for bestiality, and then a couple of days later I watched the fam/witch episode so the moral of the story is do not -- DO NOT -- drink if you're looking for a new idea. And do not drink and watch Supernatural when you're looking for an idea. You will end up with something like this mess. I'm so sorry for writing this, hell will be my final resting place.


End file.
